The present invention generally relates to positioning pattern pieces on sheet-type work material, and is more specifically directed to aligning said pattern pieces relative to one another and with a pattern defined by the work material.
During the processing of sheet-type work material, such as fabric, one or more layers of fabric are typically spread onto what is referred to by those skilled in the art of fabric processing as a spreading table. The fabric is then moved, often via a conveyor, onto a support surface forming part of a fabric processing apparatus like a cloth cutting machine.
During the spreading and subsequent movement of the fabric some stretching and misalignment often occurs. This is especially problematic when the fabric contains a pattern as any pattern pieces cut from the stretched and misaligned fabric will likewise have the pattern misaligned therein.
Generally, pattern pieces are positioned on the spread fabric in a spatial array of garment segments positioned in a cutting sequence. This spatial array of garment segments is referred to by those skilled in the pertinent art to which the present invention pertains as a xe2x80x9cmarker.xe2x80x9d Usually markers are computer generated to optimize piece pattern density and thereby minimize the waste of fabric or other spread material. In the past, computerized marker systems simply generated a marker having fairly large tolerances between adjacent pieces. The spread was first cut such that the pieces to be matched were cut including the aforementioned tolerances. These pieces were then provided to a skilled worker who would manually align the several patterns with the geometric spread design and thereafter re-cut the matched pieces. Spreads that had a geometric pattern such as plaids or stripes also caused difficulty because the clothing designer could specify an alignment of the pattern in several adjacent pieces. As a result, pieces cut from a spread having a geometric design invariably mandate higher costs due to increased waste and the use of slow, skilled labor in the cutting process.
Often, patterns need only be matched in one direction, e.g. in the warp or weft direction. An example of this is a pattern for a man""s suit, where the weft would be expected to match all the way around the garment, while at the same time, the actual weft pattern is not required to be in any particular location with respect to the pattern pieces. Accordingly, this type of matching is a relative match, and not a match to the overall fabric condition. A problem that sometimes occurs when matching pattern pieces of this type is that an operator, due to distortion of the spread work material, as well as the potential complexity of the pattern, may have difficulty visually aligning the match image to the reference image.
Based on the foregoing, it is the general object of the present invention to provide a method for matching pattern pieces, that comprise a marker, on sheet-type work material spread onto a support surface that overcomes the problems and drawbacks of prior art methods.
The present invention is directed in one aspect to a method for aligning a spatial array of pattern pieces comprising a marker onto at least one layer of sheet-type work material wherein the work material defines a pattern thereon. A work material processing apparatus is provided that defines a support surface adapted to carry at least one layer of sheet-type work material thereon. The work material is spread onto the support surface, resulting in some distortion and deviation of the work material.
Means for selectively capturing images of areal portions of said work material are employed to provide images of portions of said work material in response to commands issued from a controller in communication therewith. A display is also in communication with the controller for projecting images received by the controller in response to commands issued therefrom. The controller receives marker signals corresponding to an array of pattern pieces that include a reference signal corresponding to a reference point on a reference pattern piece. The controller is programmed to analyze the marker to be registered with the work material and the pattern defined thereon, as well as the images received from the means for selectively capturing images.
In performing the above-referenced method, the means for selectively capturing images is operated to capture an image of the work material in the area surrounding and including the reference point. In addition, the means for selectively capturing images is further operated to capture an image of the work material in an area surrounding and including a match point corresponding to a point on the marker where a matching pattern piece is initially positioned. The images of the work material at the reference point, and the work material at the matching point are superimposed, one over the other on the display.
Next, one of the images of the work material at the reference point, and the work material at the matching point is moved relative to the other until the patterns on each image match. Subsequently, the position of the matching pattern piece within the marker is then adjusted relative to the matching point, so that the pattern within a boundary defined by the matching pattern piece is alignable with that defined by the reference pattern piece.